サードパーティーの McAffe モジュール "mfe_fileaccess" が原因でサーバーがハングする

Issue

• サーバーがハングし、次のログが記録されます。

crash> log
[   19.615458] mfe_aac_100701115: loading out-of-tree module taints kernel.
[   19.616206] mfe_aac_100701115: module verification failed: signature and/or required key missing - tainting kernel
[   19.618140] AAC rule matching/reporting engine initialized successfully
[   19.618162] AAC module was inserted successfully. Version is - 10.7.1.115
[   37.958786] FileAccess module was inserted successfully. Version is - 10.7.1.115
[  960.064078] INFO: task cat:5827 blocked for more than 120 seconds.
[  960.064189] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  960.064367] cat             D ffff9d525e7d20e0     0  5827   5814 0x00000080
[  960.064370] Call Trace:
[  960.064373]  [<ffffffffb7adb1e2>] ? default_wake_function+0x12/0x20
[  960.064375]  [<ffffffffb7ac730b>] ? autoremove_wake_function+0x2b/0x40
[  960.064377]  [<ffffffffb817fb09>] schedule+0x29/0x70
[  960.064380]  [<ffffffffb817d3d8>] schedule_timeout+0x168/0x2d0
[  960.064382]  [<ffffffffb7aadce0>] ? __internal_add_timer+0x130/0x130
[  960.064385]  [<ffffffffc07ae57d>] mfe_fileaccess_set_new_entry_scan_state+0x59d/0x860 [mfe_fileaccess_100701115]
[  960.064388]  [<ffffffffb7ac72e0>] ? wake_up_atomic_t+0x30/0x30
[  960.064391]  [<ffffffffc07ae94b>] mfe_fileaccess_do_scan+0x8b/0xb0 [mfe_fileaccess_100701115]
[  960.064393]  [<ffffffffc07aeb6a>] mfe_fileaccess_sc_do_scan+0x18a/0x1a0 [mfe_fileaccess_100701115]
[  960.064396]  [<ffffffffc07ac1e4>] mfe_fileaccess_sys_open_64_bit+0x1e4/0x200 [mfe_fileaccess_100701115]
[  960.064398]  [<ffffffffb818cede>] system_call_fastpath+0x25/0x2a